Various methods are known for rendering resistance to staining and yellowing fabrics, such as carpets and drapes, made of nylon and other materials that contain free amine groups. Typical known resist agents and their use are disclosed in U.S. Pat. Nos. 4,780,099, 4,501,591, and 3,790,344. These resist agents are sulfonated naphthol- or sulfonated phenolformaldehyde condensation products. They are typified by commercially available products such as Erionol .RTM. NW (Ciba Geigy), Intratex .RTM. N (Crompton and Knowles), and Mesitol .RTM. NBS (Mobay). In use these resist agents are applied to the finished fabric, and impart excellent resistance to subsequent staining.
It is believed that resist agents bind strongly to amine dye sites and effectively block out subsequently applied stain dying molecules, leaving the fabric unstained. Thus the resist agents apparently have greater affinity to bind to amine dye-sites than dyes that would normally stain the fabric. Other related references are:
Angadi, V. S. and Chandavarkar, S. P. "New Resist Agents and Mordant for Polyamide 6 & 66." Man-made Textiles in India 24 (4): 209-214 (1981). PA0 Code of Federal Regulations (CFR). Washington, D.C., Office of the Federal Register, April, 1988. PA0 Crompton and Knowles Corporation. Material Safety Data Sheet, Product Code 0168, Reading, Pa., Crompton and Knowles Corporation, June 3, 1985. PA0 Greschler, Imrich, Malone, Creighton Paul and Zinnato, Armand P. "Method for Producing Stain Resistant Polyamide Fibers."U.S. Pat. No. 4,780,099, Oct. 25, 1988. PA0 Knop, A. and Scheib, W. Chemistry and Applications of Phenolic Resins. New York, Springer-Verlag, 1979. PA0 Mobay Corporation. Material Safety Data Sheet, Mesitol NBS, Product Code 81600, Pittsburgh, Pa., Mobay Corporation, Aug. 15, 1988. PA0 Oehrl, Lisa Louise. Interactions of the Food, Drug and Cosmetic (FD&C) Dyes with Polymer Systems. Master's Thesis, University of Delaware, Dec. 1989. PA0 Tomita, M. and Tokitaka, M. "Dihydroxyl-diphenylsulphone and Salicyclic Acid Derivatives in the After treatment of Dyed Nylon." Journal of the Society of Dyers and Colorists 96: 297-301 (June 1980).
Logically it would be expected that if a fabric not treated with a resist agent were stained, the fabric could be readily cleaned by subsequent cleaning with these resist agents. The resist agent molecules would be expected to replace the stain molecules on the amine dye sites. However, we have found this technique unsuccessful in removing stains. These resist agents do not remove and replace stain molecules on the dye sites.